Rotary tool on electric hammer



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l ROTARY TOOL ON ELECTRIC HAMMER Filed March 2, 1949 2 Sheets-Sheet 2 77/5//2 arrow/5% Patented Jan. 2, 1951 UNITED STATES PATENT OFFICE ROTARY TOOL ON ELECTRIC HAMMER Delaware Application March 2, 1949, Serial No. 79,216

(Cl. Z55-43) 4 Claims. l

This invention relates generally to electric hammers and more particularly to electric hammers having an electromagnetically operated free reciprocating piston which strikes a tool that is simultaneously rotated by a rotary electric motor carried by the hammer.

The principal object of this invention is the provision of an electromagnetic reciprocating hammer which also carries a rotary electric motor which cools the reciprocating motor and at the same time rotates the tool actuated by the reciprocating motor.

Another object is the provision of rotating the tool chuck of an electric reciprocating hammer through a pressure clutch which permits the moi tor to rotate and cool the reciprocating motor regardless of whether the tool is wedged in the work.

Another object is the provision of an electric reciprocating hammer having a rotary motor constructed to cool the reciprocating motor and rotate the tool regardless of whether the reciprocating motor is in operation or not.

Another object is the provision of an electric reciprocating hammer carrying a rotary motor connected through a clutch to rotate the reciprocating tool of the hammer, which clutch is arranged to temporarily disengage the rotary motor when the torque on the tool exceeds a predetermined amount.

Another oloject is the provision of an electric hammer motor for reciprocating a tool in axialr alignment therewith and a rotary motor carried by the hammer to rotate the reciprocating tool through a flexible connection. Such a connection may be made through a exible coupling or a resilient V-belt drive which eliminates the necessity of close tolerance in manufacturing and the eiect of vibration producing short life.

Other objects and advantages appear hereinafter in the following description and claims.

The accompanying drawings show for the purpose of exemplication, without limiting the invention or claims thereto, certain practical embodiments of the invention wherein:

Fig. 1 is a view in vertical elevation of the elec tric reciprocating hammer comprising this invention;

Fig. 2 is a side elevation of the electric hammer comprising this invention with parts broken l away;

Fig. 3 is a sectional view taken on the line 3--3 of Fig. 1;

Fig. 4 is a bottom plan view of the electric hammer as shown in Fig. 1; and

Fig. 5 is a circuit diagram illustrating the electrical connections for the operation of the electric reciprocating hammer and the rotary cooling and tool driving motor.

Referring principally to Figs. 1 and 2, the electric hammer comprises the cylindrical housing ID, having fitted to the bottom thereof the nose casting l I, which in turn has its lower portion closed by the bearing retainer plate I2, the bearing cap plate I3 and the end cover I4. At the other end of the cylindrical housing l the electric hammer is enclosed by the handle casting l5 having the rotary motor case l integrally formed therewith. The hand grip Il of the handle casting is hollow and is, provided with an electric cable connecting clamp I8 for receiving the' sheath I9 through which the electric cable Z extends from the plug 2|. The plug 2| and the cable carry three conductors 22, 23 and 24, the circuit diagram of which is illustrated in Fig. 5. The conductor 2li is connected with the electric switch 25 within the grip Il of the handle casting, which switch is actuated by the roller 25 on the end of the trigger actuating mechanism 2l'.

The reciprocating hammer motor within the housing l@ consists of the laminated electromagnetic core member 3i! that is constructed in a star arrangement on the nonmagnetic tubular barrel 3 l the bore of which encases the free moving piston or reciprocating armature 32. The stai' shaped core 33 is provided with spaced recesses for receiving the electromagnetic coils 33 and 34 which are wound on the core with suitable insulation interlocked in grooves encircling the star arranged core member Sli.

The conductor 35 connects one end of each of the coils 33 and 34 to the switch 25 wherein the circuit is completed to the conductor 24. The conductors 22 and 23, respectively, connect the other ends of the electromagnetic windings 33 and 34. When the switch 25 is closed the coils 33 and 3l'. become alternately energized by current pulsations due to the fact that each `of the conductors 22 and 23 is connected to the source of alternating current supply through oppositely set rectiers energized from an alternating current source as illustrated at 36 and 31 as shown in Fig. 5. Thus, if a sixty cycle alternating current supply is employed the electromagnetic coils 33 and 34 are alternately energized each cycle and the electromagnetic core or piston 32 will be reciprocated by the energization of the spaced electromagnetic coils.

On its upward or rearward stroke the free piston 32 engages the stop casting 38 to compress the bration from harming the motor.

spring 39 contained in the cap 49 extending within the opening of the handle casting l5. The cap 40 is provided with an annular shoulder 4| engaged by the sides of the leaf spring members 42 which are provided with aligned openings for receiving the body of the cap 45 and rest on the shoulder 4l as shown in Fig. l. The ends of the springs 42 are retained on the dametrically disposed tierods 43 by the nuts 44 as indicated in Fig. 2. A second spring 45 is likewise provided with a central opening to receive the cap 40, and is retained on the oppositely disposed tierods 43 by the nuts 4S. The oppositely disposed tierods 43 extend through aligned openings in the ears 41 of the handle casting l5 and the ears 43 `of the nose casting Il. The oppositely disposed tierods 43 hold the handle and nose castings in as sembled relation on the cylindrical housing la of the reciprocating motor. It will be noted that each of these castings is provided with flared openings for receiving the ends of the housing I0.

The rotary motor 59 is preferably a series motor mounted within the shell l of the handle casting with the upper end of the armature being retained by the bearing 5l and the lower end retained by the bearing 52, the latter of which is supported axially by the spring 53 to prevent vi- One side of the series motor is preferably connected to the conductor `22 through the wire 55 and the other side is connected to the conductor 2t through the switch 59 and the wire 54 as illustrated in Figs. 1 and 5.

The armature of the motor 5G is also provided with the fan member 56 arranged to draw air through openings in the casing around the bearing 52, which are not shown and blow air laterally to the bell end 5i of the handle casting I5 and 'thence downwardly through the reciprocating motor housing and the spaces between the star arranged magnetic core 39 to the lower end thereof wherein it is discharged laterally through the openings 58 for the purpose `of cooling the reciprocating hammer.

The shaft of the motor 59 extends downwardly to within the gear housing 59 and its lower end is provided with a pinion face as illustrated at 6I which engages the gear 62 that is formed integral with the pinion 53, which in turn engages the second idler gear 54, having a pinion 65 integral therewith for engaging the gear on the shaft 51. The idler gears of this train are supported on stub shafts, one of which is shown at 68 in Fig. l.

The shaft El extends through the aligned fianged bearings pressed in the bore of the `casting 5e and extends therebelow where it is attached to one end of the rubber coupling member 19. The other end of the rubber coupling member is connected to the shaft il, mounted on the pinion sprocket stub shaft l2. The lower end of the shaft 'H is hollow to receive the stub shaft 'l2 and has attached thereto the pinion sprocket `wheel 'E3 which is connected by means of the posed about the bore of the ring and arranged Fig. 4.

to receive a portion of the clutch ball members 8U which are contained within pockets 8| formed in the inner clutch ring member 82. As shown in Fig. 3 the inner ring 82 is provided with quadrangularly positioned pockets 8l which mate with the seats 'i9 and receive the ball members 8l) and the coil springs SS which maintain said ball members in their extended positions in said seats when properly aligned with the pockets. Thus, as the outer ring is rotated the ball members become engaged in their corresponding seats 79 and if the' friction in rotating the tool exceeds a predetermined amount of pressure exerted on the 'clutch ball members 89 by the springs, the balls are forced and are retracted back in the pockets 8i thereby permitting the outer ring Ti to slip relative to the inner ring 32.

The upper end of the nose casting l I has an opening therein for receiving the bushing 84 which abuts against the cylindrical barrel 3l and is heldin place by the bushing retaining plate B5. The bore of the bushing S4 is cylindrical to receive a 'corresponding section 55 of the chuck 81. The chuck 87 is provided with an outwardly flaring socket 8S at the outer end thereof to receive a tool and its intermediate portion is squared, as shown at in Figs. i and 3, for receiving the squared bore of the ring t2. rl'hus,v as the piston 32 of the electric hammer reciprocatesit strikes the anvil end S5 of the chuck 6i and causes the latter to bump downwardly as shown in Fig. l and move its tool into the material being cut. The weight of the hammer or the pressure exerted by the operator on the tool, together with the reactance of the material being worked on by the tool, provides for the retroaction of the tool. At the same time the rotary motor 59 rotates the chuck and the tool through the .rotary electric motor drive on one side of the electric hammer.

The lower perimetral surface of the chuck v81 is provided with a recess as indicated at 9i having oppositely disposed shoulders arranged to engage the chuck retainer tongs 92 as shown in By squeezing the ends of the retainer tongs 912 toward one another, the central circular portion of the tongs opens up to permitthe chuck 82 to be removed from the hammer. The chuck is provided with a tool drift hold 93 for the purpose of receiving a drift pin for driving the tools out of the tapered chuck 88 after the chuck has been removed from the hammer.

The nose casting Il is completely enclosed by the bearing retainer plate i2 and the block i3 and is sealed from dirt andvgrit by the rubber rings 94 and 95 mounted on the tubular shaft '16 l on either side of the bearingI i8. A similar seal 96 is likewise placed on' the top of the nose casting surrounding the shaft ll.' These seals'aie made of flexible rubber having an annular recess to receive the gripping ring that retains the seal member'tightly on the object which its surrounds. I'he aring lips oi' the iiexible rubber seals engage the adjacent stationary member to thereby form a seal.

While, for clarity of explanation, certain preferred embodiments of this invention have been shown and described, it isto be understood that this invention is capable of many modifications, and changes in the construction and arrangement -may be made. thereinV anducertain parts may be employed without conjoint use of other parts-and without departing from the spirit and scope of this invention. v

We claim:

1. An electric reciprocating tool comprising a plurality of spaced coaxially mounted electromagnetic coils adapted to be alternately energized by pulsating current, a stop coaxially mounted at one end of said coils, a tool receiving chuck coaxially mounted at the other end of said coils, a free piston to reciprocate within said coils following the magnetic impulses and strike said stop member and said tool receiving chuck, a rotary electric motor carried by the tool and connected for energization with the coils, a power take off on said rotary motor, a slip clutch rotatably supported coaxially of the coils on the end of the tool and having coaXially mounted ring members with a clutch action therebetween, a rotary driving connection between the power take off and the one ring member, and a non-round sliding connection between the other ring member and the tool chuck.

2. An electric reciprocating tool comprising a plurality of spaced coaxially mounted electromagnetic coils adapted to be alternately energized by pulsating current, a stop coaxially mounted at one end of said coils, a tool receiving chuck coaxially mounted at the other end of said coils, a free piston to reciprocate within said coils following the magnetic impulses and strike said stop member and said tool receiving chuck, a rotary electric motor carried by the tool and connected for energization with the coils, a power take off on said rotary motor, a slip clutch rotatably supported coaxially of the coils on the end of the tool and having coaxially mounted ring members with a clutch action therebetween, a rotary driving connection between the power take off and the one ring member, a flexible coupling interposed in said rotary driving connection, and a non-round sliding connection between the other ring member and the tool chuck.

3. An electric reciprocating tool comprising a plurality of spaced coaxially mounted electromagnetic coils adapted to be alternately energized by pulsating current, a stop coaxially mounted at one end of said coils, a tool receiving chuck coaxially mounted at the other end of said coils, a free piston to reciprocate within said coils following the magnetic impulses and strike said stop member and said tool receiving chuck, a rotary electric motor carried by the tool and connected for energization with the coils, a power take off on said rotary motor, a slip clutch rotatably supported coaxially of the coils on the end of the tool and having coaXially mounted ring members with a clutch action therebetween, a rotary driving connection between the power take off and the one ring member, a flexible coupling in said rotary driving connection including a resilient connection and an endless flexible member having driving engagement with aligned wheel members one of which is connected to said one ring, member, and a non-rotary sliding connection be` tween the other ring member and the tool chuck. 4. An electric reciprocating tool comprising a plurality of spaced coaxially mounted electromagnetic coils adapted to be alternately energized by pulsating current, a stop coaXially mounted at one end of said coils, a tool receiving chuck coaxially mounted at the other end of said coils, a free piston to reciprocate within said coils following the magnetic impulses and strike said stop member and said tool receiving chuck, a rotary electric motor carried by the tool, independent electrical switch means controlling the electric current supply to said rotary motor and to said coils, a power take off on said rotary motor, a slip clutch rotatably supported coaxially of the coils on the end of the tool and having coaxially mounted ring members with a clutch action therebetween, a rotary driving connection between the power take off and the one ring member, and a non-round sliding connection between the other ring member and the tool chuck.

CARL S. WEYANDT. WILLIAM V. SPURLIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,046,210 Richards June 30, 1936 2,147,045 Lembke Feb. 14, 1939 2,223,727 Homen Dec. 3, 1940 2,270,752 Drennon Jan. 20, 1942 2,403,034 Weyandt et al. July 2, 1946 2,439,230 Weyandt et al Apr. 6, 1948 Certificate of Correction Patent No. 2,536,971 January 2, 1951 CARL S. WEYANDT ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 6, line 13, for nonrotary read non-Toum;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oice.

Signed and sealed this 20th day of February, A. D. 1951.

[Smil THOMAS F. MURPHY,

Assistant Gommz'ssoner of Patents.

Certificate of Correction Patent No. 2,536,971 January 2, 1951 CARL S. WEYANDT ET AL.

It is hereby certified that error appears in the printed specication of the albove numbered patent requiring correction as follows:

Column 6, line 13, for"nonrotary read 'non-round;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oce.

Signed and Vsealed this 20th day of February, A. D. 1951.

THOMAS F. MURPHY,

Assistant 'ommz'saz'oner of Patents. 

